This invention relates to adjustable foil apparatus for a papermaking machine, and more particularly to such apparatus which includes a pair of substantially rigid foils extending laterally of a conveyor path and mounted for pivoting about longitudinal axes in mirror image movement to produce desired control of material carried on the conveyor.
In the manufacture of paper it is necessary to control the flow of fluidized material along a conveyor and to draw water therefrom. This is done generally by providing a plurality of supports which underlie the conveyor and extend laterally of the conveyor path with spaces provided therebetween through which fluids may be drawn from the papermaking stock. In the past a variety of individually adjustable foils have been proposed to provide desired dewatering and other actions in the stock being carried by the traveling conveyor.
One form of an adjustable angle foil for papermaking machine is disclosed in U.S. Pat. No. 5,169,500, issued Dec. 8, 1992. Although this patent discloses a cam adjustable rigid foil, it speaks only to the use of individual foils which have their own independent orientation and are adjusted independently of other foils in the system.
It has been found that by coordinating the adjustment of a plurality of foils improved operation may be obtained.
It is an object of the present disclosure to provide drainage foil apparatus for a papermaking machine in which a pair of foils for removing fluid from paper pulp stock are disposed adjacent each other and extend laterally of the path of an overlying conveyor, with supports and adjustment mechanism for the pair of foils being operable to produce concurrent pivoting of the foils in the pair about their respective longitudinal pivot axes to produce mirror image pivoting of the foils in the pair. In such system the foils in a pair may be selectively oriented, such that they operate together either to provide a substantially horizontal surface over which a conveyor moves, or they can be pivoted in mirror image fashion to provide either a shallow or more deeply configured V-shaped structure over which the conveyor moves.
Another object of the present disclosure is to provide such foil apparatus in which the foil angle adjustment mechanism is cam actuated in order to adjust the foil angle substantially uniformly across the entire length of the foil member.
A further object of the present disclosure is to provide such foil apparatus in which the cam actuation mechanism for one foil member in a pair is substantially a mirror image of the cam actuation mechanism of the other foil member in the pair, such that operation of the cam actuation mechanism for the pair may produce concurrent mirror image movement for the two foil members in the pair.
A still further object of the present disclosure is to provide control mechanism operatively connected to both of the foil members in a pair, with the control mechanism being operable to shift the two foil members in a pair longitudinally, with such longitudinal movement producing concurrent mirror image pivoting of the foil members in the pair about their respective longitudinal pivot axes.
An additional object of the present disclosure is to provide drainage foil apparatus for a papermaking machine in which multiple pairs of foils are provided, with the foils in each pair being pivotable in mirror image fashion relative to the other foil in its respective pair, to produce a selected angular relationship between such foils in a given pair, and a different angular relationship between the foils in another pair of foils in such system may be produced.
Yet another object of the present disclosure is to provide multiple pairs of adjustable foils disposed at different locations along the path of a papermaking conveyor, which pairs of foils may be disposed in different series of angular relationships relative to each other to provide desired actuation of material carried on the conveyor extending thereacross.
These and other objects of the present disclosure will become more fully apparent as the following description is read in conjunction with the drawings.